Toothbrush

ABSTRACT

To provide a toothbrush having fully workable long bristles on the top end for easily brushing even a comparatively flat face without making a hardly hit part and without up-and-down movement influenced by recessions and projections of bristle bunches on the rear side, all of the bristle bunches on the rear side comprise mixed bristle bunches of long and short bristles, lines connecting respectively bristle top ends of the long and the short bristles are approximately parallel to a flat planting surface on the rear side, and an effective height of main bristles on the top end of the head is higher 1 mm or more than the height of the line connecting the bristle top ends of the short bristles on the rear end, and is higher than the height of the line connecting the bristle top ends of the long bristles on the rear end.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a toothbrush having long bristles on the top end thereof, which can be easily used and efficiently remove a dental plaque.

2. Description of the Conventional Art

A toothbrush has bristles, all of which basically have the same length. Thus, when a head of the toothbrush is seen from the lateral direction, a line connecting top ends of bristle bunches is a straight line. In order to adapt the bristle tops of the toothbrush with a row of teeth having a complicated shape, for example, the following toothbrushes have been widely used conventionally. They are a toothbrush, in which bristle lengths are changed to make bristle bunches in conical shapes, or every bristle bunch is cut to have a mountain shape when seeing in the lateral direction (for example, refer to FIG. 1 in Japanese Utility Model Publication No. 62-37478) and a toothbrush having long bristles on the top end of the head (for example, refer to Japanese Utility Model Laid Open No. 63-10930, Japanese Patent Laid Open No. 5-168528). As for all of these toothbrushes, which have the bristle bunches having a conical shape, or a mountain shape made by every several bristle bunches, these have project shapes in the bristle tops at the top end of the head in many cases. The reason of this is that it is important for the toothbrush to have the long bristles on the top end of the head in order to firmly brush the inner part of a molar.

However, the toothbrush having the long bristles on the top end of the head has a problem that dental plaque removing capability is decreased, since a hardly hit part of the tooth with the bristles remains at the time of brushing a comparatively flat face such as a front tooth or the like. In order to solve this problem, a toothbrush, in which the bristles are made shorter gradually toward a handle (for example, refer to Japanese Patent Laid Open No. 4-27829) has been proposed. However, as for this toothbrush, the effect of the long bristles on the top end of the head is decreased naturally.

Further, a toothbrush, in which the head is inclined or deformed (for example, refer to Japanese Patent Laid Open No. 2000-287753, Japanese Utility Model Laid Open No. 6-36425), a toothbrush, in which every bristle bunch is cut to have a mountain shape from the top end of the head toward the handle (for example, refer to Japanese Patent Laid Open No. 2002-355120), and a toothbrush, in which the bristles are made longer again toward the rear end (for example, refer to Japanese Patent Laid Open No. 9-234114, Japanese Patent Laid Open No. 2002-325632) are also used. However, as for these toothbrushes, since only a part of the long bristles on the top end projects or the other bristle bunches than the top end have mountain shapes, the whole head of the toothbrush moves up and down unnecessarily at the time of brushing by receiving an influence of the bristles on the top end or the mountain shapes on the rear side. As a result of this, there is a problem that the effect of removing the dental plaque is decreased since the part of the long bristles on the top end does not fully work. Further, the whole head moves up and down unnecessarily by receiving the influence of the recession and projection of the bristle bunches, so that there is a problem that the brushing is hard.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide the toothbrush having the long bristles on the top end and being able to firmly brush the inner part of a molar, in which the part of the long bristles on the top end can work fully, without making the hardly hit part with the bristles at the time of brushing the comparatively flat face like in the conventional toothbrush and without unnecessarily moving at the whole head up and down at the time of brushing by the influence of the part of the long bristles on the top end or the mountain shapes of the other bristles than the top end, and furthermore, the brushing can be easily carried out.

The earnest work was carried out in order to solve the above-mentioned problems and, as a result, it was found out to complete the present invention that, in the toothbrush having the long bristles on the top end and being able to firmly brush the inner part of a molar, when all of the bristle bunches on the rear side comprise mixed bristle bunches of long bristles and short bristles, the bristle bunches on the rear side can suitably absorb the up-and-down movement.

That is, the present invention is a toothbrush comprising a head in which a plurality of bristle bunches made by bunching a plurality of bristles are planted on a planting surface, a neck and a handle in this order, wherein, when the head is seen in the lateral direction, all of the bristle bunches on the rear side comprise mixed bristle bunches of long bristles and short bristles, lines connecting respectively bristle top ends of the long bristles and the short bristles are approximately parallel to the planting surface having the straight line on the rear side, and an effective height of main bristles on the top end of the head is higher by 1 mm or more than a height of a line connecting bristle top ends of the short bristles on the rear side, and is higher than a height of a line connecting bristle top ends of the long bristles. Further, in this toothbrush, it is preferable that the difference of the height of the lines respectively connecting the bristle top ends of the long bristles and short bristles is 1 to 5 mm.

According to the present invention, in the toothbrush having the long bristles on the top end and being able to firmly brush the inner part of a molar, since all of the bristle bunches on the rear end comprise the mixed bristle bunches of the long bristles and the short bristles, the bristles on the rear end can suitably absorb the up-and-down movement. By this function, the head of the toothbrush does not unnecessarily move up and down like the conventional toothbrushes, where only the bristles on the top end project or the bristles on the rear side are formed in the mountain shapes or the like. Thus, the part of the long bristles on the tope end can certainly work, so that the effect of removing the dental plaque can be increased as compared with the conventional toothbrush having the long bristles on the top end and being able to firmly brush the inner part of a molar at the time of the brushing. Further, the toothbrush is not influenced by the mountain shapes of the bristle bunches on the rear side, and does not unnecessarily move up and down, so that the brushing can be easily carried out. Therefore, this toothbrush is excellent.

BRIEF EXPLANATION OF DRAWINGS

FIG. 1 is an explanatory view of the head to the neck of one example of the toothbrush according to the present invention when seeing in the lateral direction.

FIG. 2 is an explanatory view showing lines connecting respectively bristle top ends of the long bristles and the short bristles, and an extended line of the planting surface where the bristles bunches are planted on the rear side.

FIG. 3 is an explanatory view when the toothbrush of FIG. 1 is seen from the neck side.

FIG. 4 is an explanatory view of the head to the neck in the other example of the toothbrush according to the present invention when seeing in the lateral direction.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Hereinafter, the toothbrush according to the present invention is explained concretely with drawings.

In the drawings, 1 is a head, in which a plurality of bristle bunches is planted on the planting surface, and these bristle bunches are made by bunching a plurality of bristles. As a shape of the head, a conventional so-called general shape of the head of the toothbrush can be used, and a planting surface 3 has a rectangular shape basically when seeing from the upper side in the case of FIG. 1. Of course, as for this shape, the head having an elliptic shape or a shape of combining the above shapes can be used. Further, as for the head 1 of the toothbrush according to the present invention, when seeing in the lateral direction, the height of the bristle top ends of the planted bristles on a top end 1 a is different from that on a rear side 1 b. In this case, the top end 1 a is a part toward the top end from the center part of the head of the toothbrush when seeing the head 1 in the lateral direction, and preferably is a part being about 0.5 to 1.5 cm from the top end of the head. In addition, the rear side is a part excepting the top end of the head.

The toothbrush according to the present invention comprises the head 1, the neck, and the handle in this order. As for the neck and the handle, shapes of those in a conventional and general toothbrush can be used without especial limitation (in the drawings, the handle is omitted).

As for the toothbrush according to the present invention, all of the bristle bunches on the rear side 1 b thereof comprise the mixed bristle bunches of long bristles 2 a and short bristles 2 b. Since the bristles having the different lengths exist irregularly, the unnecessary up-and-down movement can be decreased, where this movement is caused by receiving the influence of the part of the long bristles on the top end or the mountain shape of the bristle bunches on the rear side. Although the plantation is carried out regularly in fact, for example, the long bristle and the short bristle are planted alternately, it is said to as irregularly in this case as compared with the conventional conical bristle bunches or the mountain shaped bristle bunches.

Furthermore, in the bunches, middle length bristles may exist in the range which does not to affect the present invention.

In the toothbrush according to the present invention, when seeing the head 1 in the lateral direction, it is necessary that lines 2A and 2B connecting the bristle top ends of the long bristles 2 a and the short bristles 2 b on the rear side 1 b respectively are approximately parallel to a planting surface 3B having the straight line on the rear side 1 b. Further, as shown in FIG. 3, when seeing the head 1 from the neck side of FIG. 1, it is preferable that the lines 2A and 2B connecting the bristle top ends are parallel to the planting surface 3B having the straight line on the rear side 1 b. The reason of this is to prevent the problem generated in the conventional toothbrushes, in which only the bristles on the top end of the head are long, or the bristles on the rear side have the mountain shapes or are made longer toward the rear side, or the like that the part of the long bristles on the top end moves up and down unnecessarily at the time of brushing by receiving the influence of the mountain shapes of the bristle bunches at a part except for the top end, and as a result, the part of the long bristles on the top end cannot work fully, so that the effect of removing the dental plaque at the inner part of a molar is decreased.

It is preferable that the difference of the heights of the lines 2A and 2B, connecting respectively the top ends of the long and short bristles on the rear side 1 b is 1 to 5 mm. When this difference is less than 1 mm or more than 5 mm, there is a tendency that the effect for decreasing the unnecessarily up-and-down movement is decreased by receiving the influence of the part of the long bristles on the top end, the mountain shapes of the bristles bunches on the rear side, or the like. The above difference is more preferably 1 to 3 mm.

In the toothbrush according to the present invention, when seeing the head in the lateral direction, it is important that the effective height 1A of the main bristles planted on the top end 1 a of the head 1 is higher by 1 mm or more than the height of the line 2B connecting the bristle top ends of the short bristles 2 b on the rear side 1 b, and is the same as or higher than the height of the bristle top ends 2A of the long bristles 2 a. The effective height 1A is the height being from the line 2B connecting the bristle top ends of the short bristles 2 b of the bristle bunches planted on the rear side 1 b to the tops of the bristles planted on the top end 1 a of the head 1 in the perpendicular direction. Of course, the reason of this is to use the effect of the toothbrush having the long bristles on the top end 1 a of the head 1 to be excellent in the effect of removing the dental plaque at the inner part of a molar, and this effect is based on the present invention. In addition, even when the planting surface 3A on the top end 1 a has an angle with respect to the planting surface 3B having the straight line shape on the rear side 1 b as shown in FIG. 4, the effective height 1A of the bristles on the top end is the height being from the line 2B connecting the bristle top ends of the short bristles 2 b to the tops of the bristles planted on the top end in the perpendicular direction. This effective height 1A is the same even when the bristle bunches planted on the top end 1 a are planted having an angle with respect to the planting surface 3A.

Furthermore, when the effective height 1A of the main bristles planted on the top end 1 a satisfies the above-mentioned conditions, shapes of the bristle bunches or sets of the bristle bunches on the top end are not limited. However, a shape having one projection part is preferable. For example, in an example shown in FIG. 3, when the head is seen from the side of the neck in FIG. 1, the bristle bunches planted on the top end 1 a have a mountain shape. 

1. A toothbrush comprising a head (1), where a plurality of bristle bunches made by bunching a plurality of bristles are planted on a planting surface, a neck and a handle in this order, wherein, when the head (1) is seen in the lateral direction, all of the bristle bunches on the rear side (1 b) comprise mixed bristle bunches of long bristles (2 a) and short bristles (2 b), lines (2A, 2B) connecting respectively bristle top ends of said long bristles (2 a) and said short bristles (2 b) respectively are approximately parallel to a planting surface (3B) having a straight line on the rear side (1 b), and an effective height (1A) of main bristles on the top end (1 a) of the head (1) is higher by 1 mm or more than a height of the line (2B) connecting the bristle top ends of the short bristles (2 b) on the rear side (1 b), and is higher than a height of the line (2A) connecting the bristle top ends of the long bristles (2 a).
 2. The toothbrush according to claim 1, wherein the difference of the height of the lines (2A, 2B) connecting respectively the top ends of the long bristles (2 a) and the short bristles (2 b) on the rear side (1 b) is 1 to 5 mm. 